Ahmet Davutoglu said on Monday said the extremist group was the country's "first priority" to investigate as he confirmed that the attack on a peace rally in Ankara was carried out by two suicide bombers.

"Looking at how the incident took place, we are probing Daesh as our first priority," Mr Davutoglu told NTV, a Turkish TV channel, using the Arabic acronym for Isil. Hours after his comments, Turkish media reported that the investigation into the bombing would be conducted in secret.

A court decision said lawyers would not be allowed to details of the investigation "with some exceptions", Today's Zaman reported. Similar decisions were given after previous bombings in Turkey.

"We are focusing on [Isil] in our investigations. We are zooming in on one name that points to a certain criminal organisation, but one cannot just say that we should round up an entire sleeper cell and throw them [in prison]. We must act according to the law," he said.

Turkey's prime minister Ahmet Davutoglu

Nearly 100 people were killed during Saturday's attack on a peace rally in central Ankara and nearly 250 were injured.

Thousands had gathered near the city's main train station to call for an end to the fighting between the Turkish state and PKK when the bomb exploded on Saturday morning.

Mr Davutoglu said that identifying the attackers would lead to the discovery of which group was behind the attack but insisted that officials were looking at other groups including the Kurdish guerrilla group, Kurdistan Workers' Party (PKK), and the far-Left Revolutionary People's Liberation Party-Front (DHKP-C) as "potential suspects".

Despite his comments, it is believed investigators are focusing on Isil because of the attack’s similarities with past bombings by the extremist group.

Since Saturday, dozens have been arrested in raid targeting Isil in the few days after the attack. There were suggestions that the target of the attack and the type of bomb used led investigators to an Isil faction in Adiyaman province in south-central Turkey known as Adiyaman Ones.

At least 10 members of the cell are understood to have been detained after a raid in late July. A number are also believed to be in Syria.

A still showing the moment an explosion ripped through a gathering ahead of a planned peace rally in Ankara Photo: AFP / DOKUZ 8

On Sunday, there were reports suggested the brother of a terrorist who killed 33 pro-Kurdish activists in July in a similar attack could be responsible for Saturday’s attack.

On Monday, several victims' funerals took place in Istanbul and Selahattin Demirtas, leader of the pro-Kurdish opposition Peoples' Democratic Party (HDP), attended funerals pay his respects. Many coffins were covered in red and yellow flags of the Kurdish flag.

A march in the capital to condemn the attack became an anti-government protest as tensions over government protection increase. Many blamed the attack on the government and despite the denials by the ruling Justice and Development Party led by Mr Davutoglu, many accused the authorities of neglect at how such an attack could take place in the country's capital.

Demonstrators chanted: "The killer state will be held to account!"

A relative cries over the coffin of Uygar Coskun, killed in Saturday's bombing attacks, during his funeral in Ankara Photo: Emrah Gurel/AP

Political parties cancelled their rallies ahead of the general election in less than three weeks' time.

Omer Celik, AKP spokesman, said the rallies for peace would be organised rather than political party rallies.

“Our few rallies on Friday and consecutive rallies on a routine schedule, rather than a party rally, will be organized as rallies of unity, peace and fraternity against terror," Hurriyet Daily News reported.

Mr Demirtas said his party would hold rallies because the life of an individual was more important.

"How can we hold rallies in such a bitter atmosphere? We can provide our safety by ourselves and we are not seriously worried about that. The life of one person is more important than our election success and rallies."

Despite the government saying the main suspect was Isil, Francesco Milan, a teaching fellow in in defence studies at King’s College London, said it did not mean the main organisation planned the attack.

On October 10th, two men detonated their loads amid a crowd of peace activists, killing 103 people

"The most likely organisation behind the attack seems to be Isil indeed – but there are some caveats at play. This is not necessarily an attack that has been ordered from Isil’s top echelons. Those who carried it out might very well have been trained under Isil, but this does not necessarily mean the organisation itself has planned the attack or ordered it."

"The fact that Isil currently has Turkey, as well as the Kurdish community, on its radar is beyond obvious. Since June, the organisation’s media branch (called al-Hayat Media Centre) has been publishing and disseminating 'Konstantiniyye', a monthly magazine written in Turkish, where it discusses its strategy and political approach, together with current international events, and, more importantly, giving Isil’s perspective on Turkish domestic politics.

"Tellingly, the front cover of the latest issue of “Konstantiniyye”, published on October 4, refers to the “virtue” and the 'lawfulness' of suicide bombing."